Doctors at Johns Hopkins have built a new ear for cancer patient Sherrie Walter, using cartilage from her ribs. And then implanting it in her arm. Now, this raises a few questions, the main one being, “Wait… what?”

It all began in 2008 when Walter, now 42, was first diagnosed with aggressive basal cell carcinoma, a form of skin cancer. In 2010, it returned and spread to various areas of her head. Doctors had to remove her left ear and parts of her skull tissue, CBS News reports. Patients who’ve undergone similar procedures have used prosthetic ears, but Walter didn’t see that as the best option.

“The concept of having to tape something to my skin every day didn’t feel like that was who I was,” the mother of two told ABC News. “I could just see my kids running around with it, yelling, ‘I have mommy’s ear!'”

Additionally, the fact that she was missing parts of her skull made such a procedure less feasible. So her surgeon, Dr. Patrick Byrne, an associate professor of otolaryngology-head and neck surgery at the Johns Hopkins University School of Medicine, proposed another option. Byrne and a team of doctors harvested cartilage from Walter’s ribs, shaped it into an ear and placed it under the skin of her forearm. Nourished by surrounding blood vessels, the new ear developed skin of its own and, after four months, the surgeons removed it. Next, they attached it to blood vessels in Walter’s head, sculpting tissue to affix it permanently in March of this year.

Since March, Walter’s surgeons have focused on the more cosmetic aspects of the process, shaping and sculpting the new left ear to match the right one as much as possible. Though she still needs to undergo a few more surgeries to complete the process, Walter’s hearing has been restored with the help of a special hearing aid.